Commerce Secretary Wilbur L. Ross Jr. shorted stock in a shipping firm — an investment tactic for profiting if share prices fall — days after learning that reporters were preparing a potentially negative story about his dealings with the Kremlin-linked company.

The transaction, valued between $100,000 and $250,000, took place last fall after Mr. Ross became aware that journalists investigating offshore finances were looking at his investments in the shipper Navigator Holdings, whose major clients included a Russian energy company. The New York Times emailed a list of questions about Navigator to Mr. Ross on Oct. 26.

Three business days later, Mr. Ross, a wealthy investor, opened a short position in Navigator, according to filings released on Monday by the Office of Government Ethics. The company’s stock price slid about 4 percent before Mr. Ross closed his position on Nov. 16, eleven days after the articles were published by The Times and the International Consortium of Investigative Journalists as part of the “Paradise Papers” project.

The transaction was first reported on Monday by Forbes. In interviews, ethics watchdogs raised alarms, saying the short sale created the appearance that Mr. Ross was acting on nonpublic information to potentially profit, which federal officer-holders are prohibited from doing. Mr. Ross’s office denied any impropriety, saying he disclosed the sale to the government ethics office, which “certified that the transactions documented are in compliance with federal ethics requirements.”

On Tuesday afternoon, Mr. Ross issued a statement pushing back against the notion that he had nonpublic information about Navigator before he shorted its stock. He said the reporter who contacted him was writing “about my personal financial holdings and not about Navigator Holdings or its prospects,” and therefore it was not “market-moving information.”

However, the Oct. 26 letter from The Times clearly explained, in the first paragraph, that “the story focuses mostly on your involvement with Navigator Holdings.” It went on to include 10 questions related to Navigator, Mr. Ross’s relationship with the firm and its ties to Russia.

In a traditional short sale, investors borrow stock in the open market and sell it, hoping they can later replace the borrowed shares with new ones purchased at a lower price, pocketing the difference as profit. But in the case of Mr. Ross, he and his representatives insisted that making money was not the goal of his short sale, and it could not be determined if he did.

In a separate statement, Mr. Ross, 80, said he had been in the process of divesting his holdings in Navigator when he discovered shares he did not know he had in an account set up by the company. He said because the shares were in “electronic form” he could not access them right away.

“I decided to continue selling those shares, but since I did not have physical possession of them in order to make delivery in the required time period, I technically sold them short,” he said, adding that later, when he obtained the share certificates, he delivered them to the broker to close out the transaction.

“Therefore,” Mr. Ross said, “it made no economic difference to me whether the shares went up or down between the sale date and the date I delivered them.”

It is not clear how a short sale would have accomplished Mr. Ross’s objective of divestment. Theodore Kassinger, a lawyer for Mr. Ross, said Mr. Ross thought a short sale would “eliminate the idea that he still held the shares” before he was able to dispose of them.

“He was anxious to get rid of all of his shipping holdings,” Mr. Kassinger said.

Mr. Ross came under fire after the Paradise Papers articles detailed his long relationship as a major investor in Navigator and its ties to the Russian company, Sibur, whose owners included Russian President Vladimir V. Putin’s son-in-law and an oligarch facing United States sanctions. Mr. Ross had retained an investment in Navigator after taking office, but says he has since divested it.

Virginia Canter, a former Obama White House lawyer now with Citizens for Responsibility and Ethics in Washington, said it was not clear from the government ethics office’s certification if reviewers there would have been aware of Mr. Ross’s knowledge of nonpublic information before he conducted the short sale. The ethics office would not comment on the review process.

“This new information is very disconcerting and needs to be more closely looked at,” Ms. Canter said.

A version of this article appears in print on , on Page A15 of the New York edition with the headline: Stock Deal By Official Followed News Query . Order Reprints | Today’s Paper | Subscribe